Orthodontic Appliance with Encoded Information Formed in the Base

ABSTRACT

An improved edgewise orthodontic bracket is disclosed. In one embodiment, a bracket comprises a single pair of opposing T-shaped tie wings which define an archwire slot therebetween. Notches are provided on each of the mesial and distal sides of the center leg of each T-shaped tie wing for selectively receiving a ligating device. The notches are defined in the gingival/occlusal edges of the tie wings and comprise sloped portions that extend labially towards the archwire slot. Convex sidewall portions and convex floor portions are provided in the archwire slot adjacent to the notches. The body of the bracket is interconnected to a base that includes a continuous series of characters that serve as texturing to facilitate bonding of the bracket with a tooth. A discontinuous perimeter rail may be used at the edge of the base. A method for forming a bracket is also provided.

REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/654,021, filed Oct. 17, 2012 (now U.S. Pat. No. 9,597,166,issuing Mar. 21, 2017), which is a continuation of Ser. No. 13/117,070,filed May 26, 2011 (now abandoned), which is a continuation-in-part ofU.S. patent application Ser. No. 11/782,569, filed Jul. 24, 2007 (nowU.S. Pat. No. 7,959,437, issued Jun. 14, 2011), which is acontinuation-in-part of U.S. patent application Ser. No. 10/848,929,filed May 18, 2004 (now U.S. Pat. No. 7,247,018, issued Jul. 24, 2007),which is a continuation-in-part of U.S. patent application Ser. No.10/284,016, filed on Oct. 29, 2002 (now U.S. Pat. No. 6,846,178, issuedJan. 25, 2005), all of which are also incorporated herein by thisreference.

FIELD OF THE INVENTION

This invention generally relates to edgewise orthodontic brackets and,more particularly, to edgewise brackets having enhanced treatment,comfort and ease-of-use features, as well as increased modalities and acharacter base.

BACKGROUND OF THE INVENTION

Orthodontic brackets are widely used to align teeth through theapplication of forces selectively provided by interconnected archwiresand accessories. Brackets are typically of metal, ceramic or compositeconstruction and are interconnected to either bands or bonding pads forattachment to teeth.

In edgewise brackets, an archwire passes through a labially opening,horizontal slot defined by one or more pair of opposing tie wings. Thearchwire is preshaped and sized to provide the desired forces. In eachbracket, a tie wing pair includes a gingivally extending tie wing andocclusally extending tie wing. Once placed in the slot of one or morepair of tie wings, an archwire is typically restricted therein by aligating device such as a steel or elastomeric ligature.

As orthodontic treatment objectives and techniques continue to evolve,numerous corresponding edgewise bracket designs and interconnectingaccessories have been proposed. Recently, it has been recognized that itis desirable to reduce frictional engagement between the archwire andbracket surfaces defining the archwire slot to facilitate space closureand bodily tooth movement. Similarly, in many situations, it is now agoal to reduce frictional engagement between the archwire and ligatingdevice employed to restrict the archwire within the slot. Such frictionreduction can markedly increase the rate of tooth movement and reducethe duration of the orthodontic treatment.

At the same time, patient comfort and ease-of-use considerations havebecome increasingly important. Patient comfort has been largelyaddressed by reducing bracket size to yield smaller and more smoothlycontoured brackets. Ease-of-use considerations have stimulated bracketdesigns which facilitate practitioner's bracket placement/use andaccommodate plural modalities.

Texturing of the lingual surface of orthodontic brackets has been usedto provide improved bonding between the bracket and the tooth to whichthe bracket is applied. For example, U.S. Pat. No. 5,522,725,incorporated herein by reference, concerns a method of improving thebond strength of a plastic bracket by temporarily heating and thenpermanently deforming projections located on the base of the bracket.The deformed projections interlock with adhesive when the bracket isbonded to a tooth. U.S. Pat. No. 5,595,484, incorporated herein byreference, discloses a plastic bracket having a metal reinforcementmember partly embedded in the bracket body. FIG. 13 of the >484 patentdiscloses a bracket base having eight recessed discontinuous portions 36that include molded identification characters 35. U.S. Pat. No.5,622,494, incorporated herein by reference, discloses severalstructures, including a spiral-like ridge, concentric rectangles, and aweave pattern. Upon being deformed, each structure creates an undercutstructure for forming a mechanical bond with an adhesive. However, thispatent and the other patents noted above fail to disclose a basestructure that includes lettering, symbols, or numerals that aresubstantially continuous and that functionally serve as texturing tobond the bracket to a patient's tooth. The present invention, amongstother things as described below, addresses these shortcomings.

The present invention represents significant advances in relation to theabove-noted orthodontic bracket considerations, both singularly andcombinatively, while maintaining the structural integrity of thebracket.

SUMMARY OF THE INVENTION

In one aspect of the present invention, an edgewise bracket is providedhaving a pair of tie wings defining an archwire slot therebetween, and apair of ligating support means, one defined within the mesial/distalextent of each tie wing. The ligating support means may be selectivelyemployed to reduce frictional engagement between an archwire positionedin the slot and a ligating device positioned on the ligating supportmeans and across the archwire slot. Each ligating support means includesa sloped, or angled, portion that extends labially toward the slot(e.g., labially from the gingival/occlusal periphery towards the slot),to reduce binding of a ligating device positioned thereupon. Theligating support means are preferably notches extending from thegingival or occlusal periphery of a tie wing, sized to readily receive aligating device, and preferably having a curvlinear, concaveconfiguration to further reduce binding. Typically, the opposing notchesin a given pair of tie wings will have a common center axis which isparallel to the gingival-occlusal center axis of the bracket. When thearchwire slot includes convex sidewall and/or floor portions to reducearchwire/bracket frictional engagement, the ligating support means arepreferably disposed adjacent thereto (e.g., centered upon a commongingival-occlusal plane) for enhanced treatment control.

In another aspect of the present invention, an edgewise bracket isprovided having a single pair of tie wings and two pairs of opposingligating support means defined within the mesial/distal extent of thetie wings, one pair on each of the mesial and distal sides of thebracket. The gingival/occlusal extremes of the tie wings define anelliptical configuration when viewed from the labial (“viewedlabially”). More particularly, each tie wing comprises central, mesialand distal portions which extend gingivally or occlusally, with ligatingsupport means defined between the central and mesial portions andbetween the central and distal portions, wherein the gingival/occlusaledges of such portions define an elliptical configuration. Suchconfiguration accommodates size reduction, yielding patient comfortbenefits, while preserving structural integrity and performance.

In this regard, and as will become apparent, a single pair of opposingT-shaped tie wings is preferred. That is, the “caps” of the T-shaped tiewings define an archwire slot therebetween, and the “center legs” ofeach tie wing extends gingivally or occlusally. The ligating supportmeans are preferably notches defined on the gingival/occlusal peripheryon both the mesial and distal sides of a center leg of each T-shaped tiewing. The center legs each comprise a gingivally/occlusally extendingcantilevered portion that can be conveniently employed as a stanchionfor ligature interconnection. The mesial/distal tie wing tip portions onthe outside of each notch also comprise gingivally/occlusally extendingcantilevered portions that extend a sufficient distance outward from theouter tie wing sidewalls to retain a ligating device in an arcuate seatformed under the cantilevered tie wing tip portions and center legsduring conventional ligation. Relatedly, the cantilevered center leg ofeach T-shaped tie wing should extend at least approximately the samedistance outward beyond the outer gingival/occlusal extremes of theadjacent ligating support means so as to retain a ligating device whenthe ligating support notches are selectively employed by a practitionerto support a ligating device.

In a further aspect of the present invention, an edgewise bracket isprovided having a single pair of tie wings defining an archwire slottherebetween, and an integral T-shaped hook extendinggingivally/occlusally (typically only gingivally) from one tie wing, andin perpendicular relation to the longitudinal center axis of thearchwire slot, wherein traction devices (e.g., rubber bands, springs,etc.) can be readily attached from a plurality of directions so as toaccommodate plural modalities for treatment. The T-shaped hook iscentered upon the gingival-occlusal center axis of the bracket, and ispreferably provided as a cantilevered extension of the center leg of aT-shaped tie wing so as to communicate external force moments created byinter-connected traction devices close to a tooth's root center ofresistance. Preferably, the T-shaped hook is generally flat as viewedfrom the mesial and distal aspects. Further, as viewed from the labialaspect, the T-shaped hook preferably comprises a tapered portioncontiguous to the center leg of the T-shaped tie wing, an arcuate neckportion contiguous thereto, and a head portion contiguous thereto thetapered portion, wherein a traction device may be reliably maintained inthe neck portion. That is, the tapered portion serves to restrictmovement of the traction device towards the archwire slot of thebracket, and the head portion serves to restrict disconnection of thetraction device from the T-shaped hook. The integral T-shaped hookpreferably comprises a malleable material so as to allow for selectivepivotal movement of the T-shaped hook by the orthodontic practitioner asmay be desirable for soft tissue clearance and patent comfort.

In yet another aspect of the present invention, an edgewise bracket isprovided having at least one pair of tie wings defining an archwire slottherebetween, wherein when viewed from mesial/distal aspects, thegingivally/occlusally facing outer sidewalls of the tie wing pair definea trapezoid (although rounded and/or curved sidewalls are alsocontemplated). One outer sidewall is disposed at an angle relative tothe longitudinal center plane of the archwire slot, wherein the sidewallextends labially away from such center plane. The other sidewall isdisposed substantially parallel to the archwire slot center plane. Theangled sidewall is typically disposed gingivally in both maxillary andmandibular applications. By way of example, use of the describedconfiguration and positioning allows for enhanced, early treatment ofpartially erupted upper bicuspids, wherein the archwire slot will beacceptably, gingivally positioned upon full eruption of the bicuspid.This enhances treatment and reduces demands upon the practitioner time.Further, bracket systems of this design will generally reducebracket/tooth contact between the upper and lower arches. Bracketprofile and strength can also be acceptably maintained using thedescribed configuration. The benefits associated with this trapezoidalconfiguration may be extended to orthodontic treatment applicationsrequiring positive, negative, or no torque by appropriatelyconfiguring/contouring the occlusal/gingival extent of the bracket baseor bottom.

In another aspect of the present invention, an edgewise bracket isprovided having one tie wing pair defining an archwire slot therebetweenand at least one auxiliary slot extending from a gingival edge to theocclusal edge, or vice versa, wherein the slot and shaft of theauxiliary device to be inserted into the slot have complimentaryconfigurations to restrict rotational movement therebetween. By way ofexample, the auxiliary slot may have adjoining flat inner sidewalls(e.g., defining square corners), and the auxiliary shaft may havecomplimentary flat outer sidewalls (e.g., defining square corners),wherein rotational movement therebetween is desirably restricted.

In a related aspect of the present invention, an edgewise bracket isprovided having a single tie wing pair defining an archwire slottherebetween, at least one convex portion extending labially andtransversely across the floor of the archwire slot, and at least oneauxiliary slot extending gingivally/occlusally and positioned under theconvex slot floor portion. By positioning the auxiliary slot under theconvex slot floor portion, bracket height can be advantageouslyconserved, and therefore reduced, so as to enhance patient comfort. Whentwo convex slot floor portions are provided, one on each of themesial/distal sides, twin auxiliary slots may be advantageouslypositioned so that one passes under each of the convex slot floorportions. In addition to the above-noted advantages, this bracket yieldssignificant tooth rotation capabilities. For example, in early treatmentstages, the twin auxiliary slots can be utilized with a steel ligatureto achieve rapid gross tooth rotation. As can be appreciated,complementary auxiliary slot/auxiliary shaft configurations of theabove-described nature can also be employed.

In one embodiment of the present invention, an edgewise bracket isprovided having a single set of opposing T-shaped tie wings withligating support notches defined on each side (i.e., mesially anddistally) of the center leg of each tie wing. The sidewalls defining thearchwire slot are provided to present two sets of opposing convexsidewall portions, one set on each of the mesial and distal sides of thebracket. Similarly, the floor of the archwire slot is provided topresent two convex portions extending labially and transversely acrossthe slot, one on each of the mesial and distal sides of the bracket. Byvirtue of this arrangement, the bracket yields desirable tooth rotationand alignment capabilities with reduced archwire/archwire slotfrictional engagement and selectively reduced archwire/ligating devicefrictional engagement. Further, this configuration defines a dynamicarchwire slot, wherein the archwire is allowed to maintain a “memory” ofits slot entry angle, as is now desirable. The notches each comprise aportion that extends labially outwardly from the gingival/occlusalperiphery towards the archwire slot and presents concave, curvlinearsurfaces to reduce ligature binding. The gingival/occlusal edges of thecenter legs and wing tip portions of the opposing T-shaped tie wingsdefine an elliptical configuration when viewed labially so as to reducebracket size and advance patient comfort/appearance. All prominent edgesexposed to soft tissue are preferably rounded for patient comfort.

An integral T-shaped hook of the above-described nature may beoptionally provided as a cantilevered gingival/occlusal extension of thecenter leg of either T-shaped tie wing. The T-shaped hook preferablycomprises a malleable material and preferably comprises flat linguallyand labially facing surfaces, wherein the hook can be manually pivotedto a limited extent by a practitioner relative to the center leg of thetie wing. An auxiliary slot may also be optionally provided and disposedwithin the gingival-occlusal center plane of the bracket, underlying thecenter leg portions of the opposing T-shaped tie wings. Alternatively,twin auxiliary slots may be provided, one on each side of thegingival-occlusal center plane of the bracket (i.e., mesially anddistally positioned), such slots passing under the mesial and the distalconvex slot floor portions of the archwire slot. Whether a single ortwin auxiliary slot arrangement is provided, each slot preferably has aninner-configuration which will restrict rotation of complimentaryauxiliaries inserted thereto, as described above.

The T-shaped tie wings of the bracket may also be optionally defined sothat the outer gingival/occlusal facing sidewalls of the tie wing pairdefine a trapezoid when viewed from the mesial or distal aspects. Moreparticularly, one of the outer sidewalls is disposed at an anglerelative to the longitudinal center plane of the archwire slot, and maybe perpendicular to the tie wing base surface or base/bottom surface ofthe bracket. The other outer sidewall is disposed in parallel relationto the center plane of the archwire slot.

In combination with the above-described trapezoidal configuration, thebase surface of the bracket, namely its gingival/occlusal extent, may beprovided for generating “positive torque,” “negative torque,” and “notorque.” “Positive torque” is applied to a tooth having a tooth-longaxis which projects the crown outwardly from a plane which isperpendicular to the occlusal plane and which coincides with therespective arch (e.g., mandibular or maxillary) (e.g., when the toothroot is tipped lingually). “Negative torque” is applied to a toothhaving a tooth-long axis which projects the crown inwardly from theabove-described plane (e.g., when the tooth root is tipped buccally).“No torque” is applied to a tooth having a tooth-long axis which isproperly within the above-described plane.

The configuration of the base surface of the bracket, namely itsocclusal/gingival extent, may be defined in relation to a referenceplane which coincides with that portion of the floor or bottom of thearchwire slot which engages the archwire when positioned therein (e.g.,a plane which is tangent to the two convex portions on the floor of theslot). As an example of the foregoing trapezoidal configuration and basevariations, with the “angled” outer sidewall being gingivally positionedin a maxillary application, the base may be configured to generallyextend from its gingival edge to its occlusal edge generally toward thenoted reference plane to provide for a “positive torque” on the tooth.Moreover, the base may be configured to generally extend from itsgingival edge to its occlusal edge generally away from the notedreference plane to provide for “negative torque” on the tooth.Furthermore, the base may be configured to generally extend from itsgingival edge to its occlusal edge generally parallel to the notedreference plane to provide for “no torque” on the tooth. With the“angled” outer sidewall being gingivally positioned in a mandibularapplication, the above-described non-parallel configurations of the basewould provide negative and positive torque, respectively.

The center leg of each T-shaped tie wing may also be optionally disposedat an acute angle relative to the longitudinal center axis of the slot.Such angling may be desired in applications wherein the central axis ofthe clinical crown is positioned at an acute angle relative to theocclusal plane in normal occlusion. Such angling correspondinglyfacilitates the practitioner's placement of the bracket on a tooth,wherein the axes of the center legs may be disposed along a tooth longaxis, and wherein the center axis of the bracket slot may be disposedparallel to the occlusal plane. Preferably, the mesial/distal facingedges of the center leg of each T-shaped tie wing are also parallel tothe axes of the center legs to further facilitate accurate placement ona tooth. It is also preferable for the center axes of opposing ligatingsupport notches to be disposed parallel to the gingival-occlusal centerplane of the bracket. Relatedly, for rotational purposes, it ispreferable for the apices of the opposing convex slot sidewall portionsand a convex slot floor portion correspondingly positioned on the samemesial or distal side to lie within a common plane that is disposedsubstantially perpendicular to the longitudinal center plane of thearchwire slot.

The present invention includes a substantially continuous series ofalpha-numeric characters (such as letters or numerals) or symbols (suchas company logos) that are formed in a manner such that the symbols orcharacters on the base of the bracket serve as texturing to facilitatebonding of the bracket with the tooth when the base of the bracket isattached to the tooth using an adhesive. Hereafter, the term“characters” refers to either letters, and/or numbers, and/or graphics,and/or symbols (such as logos), and/or a combination thereof.“Substantially continuous” is meant to convey the regular matrix-likeaspect of the alpha-numeric characters configured on the base so as tofacilitate a more or less uniform textured surface for bonding purposes.

One of the heretofore unappreciated aspects of the present inventioninclude the ability of a manufacturer and/or supplier of orthodonticdevices to have a trademark or other identifying character (i.e., name,symbol, part number, etc.) emblazoned on the actual device. Thiscontributes to customer confidence in purchases of “real” (vs.knock-off) products and further permits effective recalls of product inthe event of later discovered difficulties.

The characters are preferably recessed, with the space between andaround the characters projected. Thus, the projected space between thecharacters is either in contact with the tooth, or is the next surfaceclosest to the tooth's surface if a perimeter rail is present, asdiscussed below. The surface of the recessed characters is preferablyfurther away from the tooth surface than the space between thecharacters. Alternatively, the opposite arrangement may be used, wherethe space between and around the characters is recessed, and thecharacters themselves are projected.

In a separate aspect of the invention, a perimeter rail, and morepreferably, a discontinuous perimeter rail may be used at the edge ofthe base. The discontinuous perimeter rail, if used, is in contact withthe tooth surface, with the interior portion of the base patternrecessed relative to the surface of the discontinuous perimeter rail. Ifused, the perimeter rail forms a pocket to the interior of the perimeterrail that receives the adhesive. Thus, if used, a perimeter railcontacts the tooth surface, with the base pattern recessed relative tothe surface of the perimeter rail.

Various embodiments of the present invention are set forth in theattached figures and in the detailed description of the invention asprovided herein and as embodied by the claims. It should be understood,however, that this Summary of the Invention may not contain all of theaspects and embodiments of the present invention, is not meant to belimiting or restrictive in any manner, and that the invention asdisclosed herein is and will be understood by those of ordinary skill inthe art to encompass obvious improvements and modifications thereto.

Additional advantages of the present invention will become readilyapparent from the following discussion, particularly when taken togetherwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-C illustrate labial, side and end views of one embodiment ofthe present invention;

FIGS. 2A and 2B, and FIGS. 2C and 2D, illustrate labial and end views ofthe embodiment of FIGS. 1A-C when ligating support means are employed tosupport an elastomeric ligature and when ligating support means are notemployed to support an elastomeric ligature, respectively;

FIGS. 3A-C illustrate labial, side and end views of a modified versionof said embodiment of the present invention having an integral T-shapedhook and twin auxiliary slots;

FIGS. 4A-E illustrate labial, side and end views of a modified versionof said embodiment of the present invention having outer tie wingsidewalls that define a trapezoid therebetween, the end viewsillustrating various alternative configurations of the base to providefor positive, negative, and no torque on a tooth;

FIGS. 5A-C illustrate labial, side and end views of the modifiedembodiment of the present invention illustrated in FIGS. 4A-C, with acentral auxiliary slot;

FIGS. 6A-C illustrate labial, side and opposing end views of themodified embodiment of the present invention illustrated in FIGS. 4A-C,with an angulated gingival-occlusal center axis and twin auxiliaryslots;

FIGS. 7A-B illustrate two views of an exemplary auxiliary device useablewith the auxiliary slots of the present invention;

FIG. 8 is a rear view of the base of the orthodontic bracket shown inFIG. 4B without the flanges, and including a character base patternforming an aspect of the present invention;

FIG. 9A-B are cross-sections taken along line 9-9 of FIG. 8;

FIG. 10 is a rear view of the base of the orthodontic bracket shown inFIG. 4B with the flanges, and including a character base pattern;

FIG. 11A is a rear view of the base of the orthodontic bracket shown inFIGS. 1B and 5B with the flanges, and including a character base patternand an auxiliary slot without a character pattern in the auxiliary slot;

FIG. 11B is a rear view of the base of the orthodontic bracket shown inFIGS. 1B and 5B with the flanges, and including a character base patternand an auxiliary slot with a character pattern in the auxiliary slot;

FIG. 12A is a rear view of the base of the orthodontic bracket shown inFIG. 6B with flanges, and including a character base pattern and twinauxiliary slots without a character pattern in the auxiliary slots;

FIG. 12B is a rear view of the base of the orthodontic bracket shown inFIG. 6B with flanges, and including a character base pattern and twinauxiliary slots with a character pattern in the auxiliary slots;

FIG. 13 is a plan view of the of the bracket of FIG. 4B without flanges,and including a discontinuous perimeter rail;

FIG. 14 is a rear view of the base of the bracket shown in FIG. 13;

FIGS. 15A-B are cross-sections taken along line 15-15 of FIG. 14;

FIG. 16 is a rear view of the base of the orthodontic bracket shown inFIG. 4B with flanges, and including a character base pattern and adiscontinuous perimeter rail;

FIG. 17 is a cross-sectional view of a bracket and a mold used to formthe bracket;

FIG. 18 is a separate embodiment of the present invention comprising analternate base pattern; and

FIG. 19 is a labial view of a bracket having a labial positionedcharacter pattern on its flange portions.

The drawings are not necessarily to scale.

DETAILED DESCRIPTION

One embodiment of the body of an edgewise bracket 10 of the presentinvention is illustrated in FIGS. 1A-C and 2A-D, with variousmodifications, modalities and an exemplary auxiliary reflected by FIGS.3A-C, 4A-E, 5A-D, 6A-C and 7A-B, and with various base structures and asillustrated in FIGS. 8-18. Corresponding features are referenced bycommon reference numerals.

The edgewise bracket 10 comprises two integral, opposing T-shaped tiewings 12 and 14 having a common base portion and base surface 16, anddefining an archwire slot 18 therebetween. By way of example only, aflange 32 may be adjoined to the bracket 10 for subsequent attachment toa band. Alternatively, the bracket may be adjoined to a bonding pad (notshown).

Two sets of opposing ligating support means 20 and 22, are provided,each set comprising a gingivally disposed notch and occlusally disposednotch on the gingival and occlusal edges of tie wings 12,14,respectively. Each ligating support means has a sloped portion 24 andtop land portion 26. The sloped portions 24 have concave, curvlinearsurfaces.

Each of the T-shaped tie wings 12,14 comprises a cantilevered centralleg portion 28 centered upon the gingival-occlusal center axis (lyingwithin plane AA) of the bracket 10 and cantilevered mesial/distal wingtip portions 30, with the above-noted top land portions 26integral-therebetween. The gingival/occlusal extremes of the center leg28 and mesial/distal wing tip portions 30 of the tie wings 12,14 define,from the labial aspect, an elliptical configuration E. In this regard,cantilevered wing tip portions 30 extend a sufficient distance d outwardfrom the outer sidewalls 34, 36 of the tie wings 12, 14, respectively,to retain a ligating device in an arcuate seat 38 formed under thecantilevered tie wing tip portions 30 and center legs 28. Relatedly, thecantilevered center leg 28 of each T-shaped tie wing 12, 14, extends adistance f beyond the outer gingival/occlusal extreme of the ligatingsupport means 20 adjacent thereto, such distance f being at leastapproximately as great as the distance d.

The sidewalls defining the archwire slot 18 comprise two sets ofopposing convex portions 42 to reduce frictional engagement with anarchwire. Similarly, the floor of archwire slot 18 is provided with twoconvex portions 44 extending transversely across the archwire slot 18 toreduce frictional engagement with an archwire. As illustrated in FIGS.1A-C, the ligating support means 20, convex slot sidewall portions 42,and convex slot floor portion 44 disposed on the same side of thegingival-occlusal center plane AA may have a common center axis (lyingwithin plane BB). As such, frictional engagement between an archwire andthe slot walls and base, and between an archwire and ligating devicesupported on ligating support means 20 occurs in a limited region aboutplane BB.

An optional auxiliary slot 70 may be provided to receive a complimentaryauxiliary device, such as the exemplary auxiliary 74 illustrated inFIGS. 7A and 7B. The inner sidewalls of auxiliary slot 70 andinterfacing shaft portion 76 of the exemplary auxiliary 74 arepreferably configured to restrict rotational movement therebetween. Asillustrated, a complimentary square-angled configuration may beemployed. Additionally, the auxiliary 74 preferably comprises anextending portion 78 having an outer configuration which will not fitinto auxiliary slot 70, thereby facilitating placement and removal.

FIGS. 2A-B illustrate the interface between an archwire X andelastomeric ligating device Y when both sets of the ligating supportmeans 20 of the embodiment of the present invention illustrated in FIGS.1A-C are utilized. FIGS. 2C-D illustrate the interface between anarchwire X and elastomeric ligating device Y when neither of theligating support means 20 of such embodiment are utilized. As will beappreciated by those in the art, there are different treatmentsituations where each of these modalities may be desired. Additionally,the provision of a set of ligating support means 20 on each of themesial and distal sides of the bracket 10 allows a practitioner toutilize one set but not the other, as may be desirable.

In FIGS. 3A-C an integral T-shaped hook 50 is provided as an extensionto the center leg 28 of one of the T-shaped tie wings 12. The T-shapedhook 50 preferably comprises flat lingual and labial surfaces (see FIG.3C), and is preferably malleable to allow for pivotal movement relativeto center leg 20. The T-shaped hook 50 preferably comprises a taperedportion 52, arcuate neck portion 54 and head portion 56, wherebyretention of a traction device in neck portion 54 is enhanced.

Twin auxiliary slots 80 may be optionally provided for receipt of anauxiliary device, such as the exemplary auxiliary 74 shown in FIGS.7A-B. The twin auxiliary slots 80 are beneficially disposed under theconvex slot floor portions 44. The configuration of slots 80 andexemplary auxiliary 74 may be as described above to restrict rotationalmovement therebetween and facilitate placement/removal.

FIGS. 3A-C also illustrate optional saddles 60 which can be provided inthe support landing portions 26 for receiving a ligating device. It isbelieved that such saddles 60 may be beneficial in certain earlytreatment situations for purposes of retaining an undersized archwire inthe desired position for rotational purposes.

In FIGS. 4A-E, the outer sidewall 34 of tie wing 12 and outer sidewall36 of tie wing 14 define a trapezoid therebetween. Specifically, outerside wall 34 is angled relative to the longitudinal center plane CC ofthe archwire slot 18, and the outer tie wing sidewall 36 is disposed inparallel relation to the center plane CC of the archwire slot 18. Byvirtue of this arrangement, the outer sidewall 34 may be, for example,advantageously disposed gingivally on partially erupted upper bicuspids.Further, bracket systems employed by this configuration will generallyreduce bracket/tooth contact between upper and lower arches.

Referring in more detail to FIGS. 4C-E, the trapezoidal configuration ofthe bracket 10 is illustrated with three alternate configurations forthe base portion 16. Generally, the configuration of the base portion16, namely its occlusal/gingival extent, may be defined in relation tothe reference plane RP. As can be seen in FIGS. 4B-E, the referenceplane RP coincides with that portion of the bottom or floor of thearchwire slot 18 which engages the archwire when positioned therein(e.g., a plane which is tangent to the two convex slot floor portions44.

The configurations of base portion 16 in FIGS. 4C-E allow a practitionerto provide positive, negative, and no torque on a tooth of a particularorientation. Initially, with the tie wing 34 being gingivally positionedin a maxillary application, the base portion 16 of FIG. 4C would be usedto provide for “positive torque” on a tooth, the base portion 16 of FIG.4D would be used to provide for “negative torque” on a tooth, and thebase portion 16 of FIG. 4E would be used to provide for “no torque” on atooth. More particularly, in the case of the bracket 10 of FIG. 4C thebase portion 16 would thereby extend from its gingival edge to itsocclusal edge generally toward the reference plane RP in order toproperly orient the archwire slot 18 on the orthodontic patient.Moreover, in the case of the bracket 10 of FIG. 4D the base portion 16would thereby extend from its gingival edge to its occlusal edgegenerally away from the reference plane RP in order to properly orientthe archwire slot 18 on the orthodontic patient. Furthermore, in thecase of the bracket 10 of FIG. 4E the base portion 16 would therebyextend from its gingival edge to its occlusal edge generally parallelwith the reference plane RP in order to properly orient the archwireslot 18 on the orthodontic patient.

In the event that the tie wing 36 is gingivally positioned in amandibular application, the base portion 16 of FIG. 4C would provide for“negative torque” on the tooth, the base portion 16 of FIG. 4D wouldprovide for “positive torque” on the tooth, and the base portion 16 ofFIG. 4E would provide “no torque” on the tooth.

The modified embodiment illustrated in FIGS. 4A-C is shown withadditional features in FIGS. 5A-C and 6A-C, although the bracket 10 ofFIGS. 4D-E could be similarly modified as well. In FIGS. 5A-C, a centralauxiliary slot 70 is provided. FIGS. 6A-C illustrate the inclusion oftwin auxiliary slots 80 for receiving of auxiliary devices. The twinvertical slots 80 are disposed so that each passes under one of theconvex slot floor portions 44.

In the version shown in FIGS. 6A-C, it should also be appreciated thatthe gingival-occlusal center axis of the bracket (lying within plane AA)can be disposed at an acute angle relative to center axis of archwireslot 18 (lying within plane CC). More particularly, center legs 28 maybe centered upon the gingival-occlusal center axis and may be providedwith distal/mesial surfaces 84 which are parallel to thegingival-occlusal center axis thereby facilitating placement of thebracket. In this modified version, it should be recognized that whilethe center plane BB of the ligating support means 20 is also disposedparallel to the gingival-occlusal center axis, the apices of the convexslot sidewall portions 42 and convex slot floor portion on each ofmesial and distal sides lie in a plane which is perpendicular to thearchwire slot center plane CC. Relatedly, it should be appreciated that,when a T-shaped hook is utilized (such as the T-shaped hook 50illustrated in FIGS. 3A-C above), the center axis thereof will bedisposed perpendicularly to the center axis of the archwire slot 18 andat an angle relative to the gingival-occlusal center axis of the bracket10.

Referring now to FIG. 8, another aspect of the present invention isshown. FIG. 8 depicts an enlarged rear elevation view of the rearsurface or base 16 of bracket 10, as shown in FIG. 4B, but withoutflanges 32. Base 16 includes gingival edge 86 a, distal edge 86 b,occlusal edge 86 c, and mesial edge 86 d. Within the interior of edges86 a,86 b,86 c, and 86 d is interior region 88. Interior region 88includes a projected surface 90 and a recessed surface 92, as depictedin FIGS. 9A and 9B. The projected surface 90 of the interior region 88is a surface that is both substantially parallel to the tooth's surfaceand closest to the tooth's surface upon attachment of the bracket 10 tothe tooth. The recessed surface 92 is a surface of the interior region88 that is also substantially parallel to the tooth's surface, but isfurther away from the tooth's surface than the projected surface 90 uponattachment of the bracket 10 to the tooth. The recessed surface 92 ispreferably recessed between about 0.009 to 0.011 inches relative to theprojected surface 90, and more preferably, the recessed surface isrecessed about 0.010 inches relative to the projected surface 90.

Characters 94 and intermediate space 96 extend substantiallycontinuously within interior region 88, between edges 86 a,86 b,86 c,and 86 d. The pattern of characters 94 may be repeating, such as theletters ARMO@ 7 shown in FIG. 8, or they may be a non-repeating seriesof characters 94. Alternately, the characters may be a set ofinformation regarding the bracket 10, such as its intended installationlocation, manufacturer, date of manufacturer, model number, etc. As oneof skill in the art will appreciate, the provision of particular usefulinformation on the base, and having such encoded information perform auseful function with respect to the use of the device, is itself a noveland nonobvious characteristic of the present invention. Regardless ofthe nature of the characters 94 actually used, in a preferredembodiment, the base 16 does not have a grid between the characters 94.That is, in contrast to the bracket base shown in FIG. 13 of U.S. Pat.No. 5,595,484, the base 16 of the present invention does not have a gridor lattice within which the characters reside. Rather, the presentinvention uses characters 94 and a relatively irregular, non-grid likeintermediate space 96 to cover the entire interior region 88. Thecharacters 94 and intermediate space 96 thus function directly as thetexturing that works in combination with the adhesive to bond thebracket to the tooth.

In a separate aspect of the present invention, the characters 94 may beangled at any orientation relative to the edges 86 a,86 b,86 c, and 86d. More specifically, the characters may be oriented parallel with edges86 a and 86 c, or perpendicular to edges 86 a and 86 c. Likewise, thecharacters may be oriented parallel with edges 86 b and 86 d, orperpendicular to edges 86 b and 86 d. Alternately, the characters 94 maybe oriented at an angle relative to edges 86 a,86 b,86 c, and 86 d. Asan example without limitation, FIG. 8 illustrates that the characters 94are oriented at an angle θ of about 15 degrees relative to edges 86 aand 86 c, and at an angle of about 75 degrees relative to edges 86 b and86 d.

Character length “L” and width “W” may vary considerably. Referring nowto FIG. 8, in a preferred embodiment, in plane view the length L of eachcharacters 94 is about 0.034 to 0.038 inches, and more preferably, about0.036 inches. The width W of each character 94 varies with the lengthand with the specific character type. For example, in the characterstring “RMO” 7 shown in FIG. 8, an “M” is typically wider than an “R” oran “O”.

For each character 94, the line width “lw” preferably ranges betweenabout 0.008 to 0.010 inches, where line width lw is the width of theline forming each individual character 94. Typically, line width lw willvary with character length L. Therefore, shorter characters 94 willtypically have thinner line widths lw. Obviously, logos, symbols andgraphics will have lengths L, widths W, and line widths lw as requiredto form each individual type of shape.

The total surface area in rear elevation view, or the exterior surfaceof the base 16 is defined herein as the area in rear elevation viewbetween edges 86 a,86 b,86 c, and 86 d for the base surfaces parallel tothe tooth's surface. Whether the characters 94 are letters, numbers,logos, symbols, or graphics, preferably the recessed surface 92comprises between about 50% to 60% of the total surface area of the base16, and more preferably, about 55% of the total surface area of base 16.Correspondingly, preferably the projected surface 90 comprises betweenabout 40% to 50% of the total surface area of the base 16, and morepreferably, about 45% of the total surface area of the base 16.

Projected surface 90 and recessed surface 92 are comprised of characters94 and intermediate space 96, which is situated between and aroundcharacters 94. Characters 94 may occupy the projected surface 90 of thebase 16, but preferably occupy the recessed surface 92 of the base 16.Alternatively, intermediate space 96 may occupy the recessed surface 92of base 16, but preferably occupy the projected surface 90 of base 16.Thus, in a preferred embodiment, upon attachment of the bracket 10 tothe surface of a patient's tooth, intermediate space 96 is the projectedsurface 90 that is closer to the tooth surface than the characters 94that are situated along the recessed surface 92. Separation between thecharacters 94 and intermediate space 96 is formed by bracket characterwalls 98 that are generally perpendicular or steeply sloped surfacesdisposed between the characters 94 and the intermediate space 96. Asshown in FIG. 9A, the projected surface 90 contacts the tooth surfaceupon attachment of the bracket 10 in the direction of arrows A2 to thepatient's tooth T. Thus, as shown in FIG. 9A, when the intermediatespace 96 occupies the projected surface 90, the intermediate surface 96is closest to the tooth surface, and the location of characters 94 isrecessed relative to the location of intermediate space 96. In contrast,FIG. 9B presents the same cross-sectional view of base 16 as that shownin FIG. 9A, but with the characters 94 and intermediate space 96inverted. That is, in this modified arrangement, the location ofintermediate space 96 is recessed relative to the location of thecharacters 94. Therefore, the characters 94 contact the tooth surfaceupon attachment of the bracket 10 in the direction of arrows A2 to thepatient's tooth T.

Referring now to FIGS. 4B and 10, a bracket 10 with a continuous anduninterrupted base 16 and flanges 32 is shown. When flanges 32 areincorporated into the base 16 having characters 94, the characters 94are preferably extended across the entire rear surface of the bracket10. Preferably, the characters 94 form the recessed surface 92 as shownin FIG. 9A, and the intermediate space 96 forms the projected surface90. Whether the characters 94 are letters, numbers, logos, symbols, orgraphics, preferably the recessed surface 92 comprises between about 50%to 60% of the total surface area of the base 16 and the flanges 32, andmore preferably, about 55% of the total surface area of base 16 and theflanges 32. Correspondingly, preferably the projected surface 90comprises between about 40% to 50% of the total surface area of the base16 and the flanges 32, and more preferably, about 45% of the totalsurface area of the base 16 and the flanges 32. These preferred valueshave been found to provide better adhesion characteristics between thebracket and the tooth to which it is applied.

Referring again to FIGS. 1B and 5B, a bracket 10 having a base 16 with asingle auxiliary slot 70 is shown. A rear plan view of the base of FIGS.1B and 5B is shown in FIGS. 11A and 11B, wherein the rear of the bracket10 incorporates characters 94. For the bracket shown in FIG. 11A, whenflanges 32 are incorporated into the base 16 having characters 94, thecharacters 94 are preferably extended across the entire rear surface ofthe bracket 10, with the exception of the area occupied by the auxiliaryslot 70. Consistent with the other embodiments described above,preferably the characters 94 form the recessed surface 92 as shown inFIG. 9A, and the intermediate space 96 forms the projected surface 90.Whether the characters 94 are letters, numbers, logos, symbols, orgraphics, preferably the recessed surface 92 comprises between about 50%to 60% of the total surface area of the base 16 (not including the areaoccupied by the auxiliary slot 70) and the flanges 32, and morepreferably, about 55% of the total surface area of base 16 (notincluding the area occupied by the auxiliary slot 70) and the flanges32. Correspondingly, preferably the projected surface 90 comprisesbetween about 40% to 50% of the total surface area of the base 16 (notincluding the area occupied by the auxiliary slot 70) and the flanges32, and more preferably, about 45% of the total surface area of the base16 (not including the area occupied by the auxiliary slot 70 and theflanges 32. These preferred values have been found to provide betteradhesion characteristics between the bracket and the tooth to which itis applied.

Referring now to FIG. 11B, the bracket includes a character pattern 94within the area of the auxiliary slot 70. When characters 94 areintegrated into the auxiliary slot 70, the characters 94 may havedifferent dimensions than that of the remaining base 16. Preferably, thecharacter pattern 94 may be finer, thus limiting the probability of atool to be inserted therein from hanging-up or catching on thecharacters 94. Alternatively, the character pattern 94 in the auxiliaryslot 70 may have a rounded (not shown) or alternatively texturedexterior surface that advantageously interacts with the tool to beinserted therein.

Referring again to FIG. 3B, a bracket 10 having a base 16 with twinauxiliary slots 80 is shown. A plan view of the rear of FIG. 3B is shownin FIGS. 12A and 12B, wherein the rear of the bracket 10 incorporatescharacters 94. For the bracket shown in FIG. 12A, when flanges 32 areincorporated into the base 16 having characters 94, the characters 94are preferably extended across the entire rear surface of the bracket10, with the exception of the area occupied by the twin auxiliary slots80. Consistent with the other embodiments described above, preferablythe characters 94 form the recessed surface 92 as shown in FIG. 9A, andthe intermediate space 96 forms the projected surface 90. Whether thecharacters 94 are letters, numbers, logos, symbols, or graphics,preferably the recessed surface 92 comprises between about 50% to 60% ofthe total surface area of the base 16 (not including the area occupiedby the twin auxiliary slots 80) and the flanges 32, and more preferably,about 55% of the total surface area of base 16 (not including the areaoccupied by the twin auxiliary slots 80) and the flanges 32.Correspondingly, preferably the projected surface 90 comprises betweenabout 40% to 50% of the total surface area of the base 16 (not includingthe area occupied by the twin auxiliary slots 80) and the flanges 32,and more preferably, about 45% of the total surface area of the base 16(not including the area occupied by the twin auxiliary slots 80) and theflanges 32. These preferred values have been found to provide betteradhesion characteristics between the bracket and the tooth to which itis applied.

Referring now to FIG. 12B, the bracket includes a character pattern 94within the area of the auxiliary slots 80. As with the single auxiliaryslot 70 shown in FIG. 11B, when characters 94 are integrated into theauxiliary slots 80, the characters 94 may have different dimensions thanthat of the remaining base 16. Preferably, the character pattern 94 maybe finer, thus limiting the probability of a tool to be inserted thereinfrom hanging-up or catching on the characters 94. Alternatively, thecharacter pattern 94 in the auxiliary slots 80 may have a rounded (notshown) or alternatively textured exterior surface that advantageouslyinteracts with the tool to be inserted therein.

Referring again to FIG. 4B, in yet a separate aspect of the invention,the bracket 10 may include a curved base 16. The base 16 may be set at avariety of angles depending upon the curvature of the patient's toothsurface.

Referring now to FIGS. 13-15A,B in yet a separate aspect of theinvention, base 16 preferably includes a perimeter rail, and morepreferably, a discontinuous perimeter rail. The discontinuous perimeterrail preferably includes at least one corner segment, and morepreferably, a plurality of corner segments, including a distal/gingivalcorner 100 a, a gingival/mesial corner 100 b, a mesial/occlusal corner100 c, and an occlusal/distal corner 100 d. Corners 100 a,100 b, 100 c,and 100 d are preferably between about 0.008 to 0.011 inches in widthAcw@, and more preferably, are about 0.085 inches wide. Each corner 100a,100 b, 100 c, and 100 d is separated from the other corners segmentsby a distance or a cavity. Preferably, the discontinuous perimeter railalso includes at least one straight segment, and more preferably, aplurality of straight segments. More preferably yet, two straightsegments are provided, namely a gingival straight segment 102 a and anocclusal straight segment 102 c. The gingival straight segment 102 a isseparated from the distal/gingival corner 100 a and the gingival/mesialcorner 100 b by a cavity or a distance Ad₁@ of about 0.008 to 0.011inches, and more preferably, by a distance d₁ approximately equal to thewidth cw of the discontinuous perimeter rail, or about 0.0085 inches.Similarly, the occlusal straight segment 102 c is separated from themesial/occlusal corner 100 c and the occlusal/distal corner 100 d by acavity or distance d₁ of about 0.008 to 0.011 inches, and morepreferably, by a distance d₁ approximately equal to the width cw of thediscontinuous perimeter rail, or about 0.0085 inches. Although base 16will function without a perimeter rail, the discontinuous perimeter railin combination with characters 94 increases the bonding strength ofbracket 10 when it is attached to a tooth using an adhesive.

Referring again to FIG. 13, although it may be present, in a preferredembodiment, the discontinuous perimeter rail does not include a distalstraight segment between the distal/gingival corner 100 a and theocclusal/distal corner 100 d. In addition, in a preferred embodiment,the discontinuous perimeter rail does not include a mesial straightsegment between the gingival/mesial corner 100 b and the mesial/occlusalcorner 100 c.

Still referring to FIG. 13, in a preferred embodiment, the perimeterrail is preferably positioned within the base area defined by edges 86a,86 b,86 c, and 86 d. More specifically, corners 100 a,100 b,100 c, and100 d, as well as straight segments 102 a and 102 c of the discontinuousperimeter rail are all disposed within the interior of the area definedby base edges 86 a,86 b,86 c, and 86 d. The total surface area in rearelevation view, or the exterior surface of the base 16 is defined hereinas the area in rear elevation view between edges 86 a,86 b,86 c, and 86d for the base surfaces parallel to the tooth's surface. Where adiscontinuous perimeter rail is used, the discontinuous perimeter railportions 100 a,100 b,100 c, 100 d, 102 a and 102 c comprise betweenabout 12% to 16% of the total surface area of the base 16, and morepreferably, about 14% of the total surface area of base 16. Whether thecharacters 94 are letters, numbers, logos, symbols, or graphics, when adiscontinuous perimeter rail is present, preferably the recessed surface92 comprises between about 45% to 50% of the total surface area of thebase 16, and more preferably, about 48% of the total surface area ofbase 16. Correspondingly, when a discontinuous perimeter rail ispresent, preferably the projected surface 90 comprises between about 35%to 40% of the total surface area of the base 16, and more preferably,about 38% of the total surface area of the base 16.

Referring now to FIG. 15A, a cross-sectional view along line 15-15 asshown in FIG. 13 is provided. The cross-sectional view of FIG. 15A showsthe gingival straight segment 102 a and the occlusal straight segment102 c along the gingival and occlusal edges of the bracket 10. FIG. 15Aalso shows that the rail surface 104 is disposed beyond the projectedsurface 90. In the preferred embodiment depicted in FIG. 15A, theprojected surface 90 is comprised of the intermediate space 96 betweencharacters 94, while the recessed surface 92 is comprised of thecharacters 94. The rail surface 104 preferably projects a distance As@of about 0.002 to 0.004 inches beyond the projected surface 90, and morepreferably, the rail surface 104 projects about 0.003 inches beyond theprojected surface 90. Thus, when bracket 10 having a discontinuous railis placed with its base 16 in contact with a patient's tooth, the railsurface 104 contacts the patient's tooth. The discontinuous rail thusforms a pocket for the collection of adhesive. Upon application of thebracket 10 to a patient's tooth, the openings between the perimeter railpermit excess adhesive to escape under the applied pressure, therebypreventing the bracket 10 from having an adhesive layer that is toothick and moving away from the tooth as a result of increased hydraulicpressure formed within the adhesive pocket when the bracket is firstpressed against the tooth to which it is being applied. Thus, thediscontinuous structure of the perimeter rail improves the bondingstrength between the bracket and the patient's tooth because it allowsexcess adhesive to escape during the application of the bracket 10 tothe tooth's surface. Furthermore, as shown in FIG. 15B, the differencein distance provided by the projection of the perimeter rail beyond theprojected surface 90 allows a layer of adhesive 106 to bond between theprojected surface 90 and the tooth's surface. Thus, a layer of adhesiveis formed within the entire interior area 88 of the base that is nototherwise occupied by the discontinuous perimeter rail segments 100 a-d,and 102 a and 102 c. This further improves bonding between the bracket10 and the tooth's surface.

Referring now to FIG. 16, for those brackets that include flanges 32adjacent the base 16, the perimeter rail is preferably located along theoutermost edges of the flanges 32. Thus, the discontinuous perimeterrail portions 100 a,100 b,100 c, and 100 d will occupy the cornersformed at the outer limits of the flanges 32. In addition, the gingivalstraight segment 102 a and the occlusal straight segment 102 c willoccupy portions of the gingival edge 86 a and the occlusal edge 86 c,respectively. The gingival straight segment 102 a and the occlusalstraight segment 102 c can occupy area along both the base 16 and theflanges 32, depending upon the chosen perimeter rail configuration. Inaddition, for those brackets that include a single auxiliary slot 70 ortwin auxiliary slots 80, the perimeter rail is preferably not presentalong the alignment of the auxiliary slot 70 or slots 80.

In yet a separate aspect of the invention, the surface finish of thebase is manufactured to provide a finish having textural characteristicssuited for use with characters 94. More particularly, the presentinvention includes a method of making the bracket 10 and its base 16that is specifically suited for a bracket 10 with a base 16 and flanges32 (optional) having a continuous pattern of characters 94. In apreferred embodiment, a one-piece molded metal injected bracket 10 ismanufactured from a mold 108. As known to those skilled in the art, themold 108 is produced by electrical discharge machining using shapedelectrodes to form the mold 108 itself. More specifically, the shapedelectrodes are formed to correspond to the desired shape of at least aportion of one of the exterior surfaces of the bracket 10, such as theexterior surface that forms base 16. The shaped electrodes are thencharged and placed in contact with a metal shape that will form aportion of mold 108 for production of the actual brackets 10. Morespecifically, the charged electrode Aburns@ the desired bracket patterninto the metal shape, thus forming a portion of mold 108. The mold istypically formed from a top and a bottom portion that is then assembledto form a hollow space that defines the bracket 10. The mold 108 is thenused to manufacture a bracket 10 by injecting the mold 108 with thebracket material, such as molten stainless steel, via an injectionchannel that passes through mold 108 to the interior hollow regiondefining the bracket form. The molten stainless steel is allowed to cooland harden, and then the mold 108 is separated and molded bracket 10 issubsequently ejected from the mold 108.

In order to adequately bond the bracket 10 having a continuous patternof characters 94 to the tooth surface using an adhesive, the surfaces ofthe base 16 that are parallel to the tooth's surface are preferablyrelatively rough. However, if the surfaces of mold 108 corresponding tothe base 16 of bracket 10 are too rough, the actual bracket 10 cannot beejected from the mold 108 during the bracket manufacturing process.Thus, in this separate aspect of the invention, the mold 108 ispreferably manufactured and processed to have appropriate surficialroughness textures along its corresponding base surfaces.

Referring now to FIG. 17, the mold 108 has a base that includes moldrecessed surface 110 and mold projected surface 112, which correspond tothe projected surface 90 and the recessed surface 92 of bracket 10,respectively. Preferably, mold recessed surface 110 and mold projectedsurface 112 have a surface finish of approximately a maximum of 110.8micro-inches. In contrast, preferably the mold character walls 114 ofmold 108 that form the generally sloped or perpendicular surfacesbetween characters 94 and intermediate spaces 96 of bracket 10 arepolished. More specifically, the mold character walls 114 of mold 108are preferably hand polished to a relatively smooth and polished finish,preferably using a ruby stone, although other means may be employed.Upon manufacture of a bracket 10 from mold 108, the hand polishedcharacter walls 114 of the mold 108 allow the actual bracket 10 to beejected from the mold 108 because the character walls 98 of bracket 10are formed to have a smooth and polished finish that corresponds to thepolished mold character walls 114 from which they were formed. Thus, thebracket 10 may be ejected from mold 108 without sticking to the mold 108and thereby preventing ejection from occurring, or bending or otherwisecausing detrimental structural damage to the bracket 10 during theejection process. An ejector pin (not shown) may be used to aid theejection process, wherein the ejection pin forceably separates thebracket 10 from the mold 108 by pushing base 16 away from mold 108.

Where a perimeter rail is used, the mold 108 preferably includes adeeper recessed surface 116 corresponding to the perimeter rail surface104. The deeper recessed surface 116 is surficially textured to providetexturing to the perimeter rail surface, which in turn improves bondingbetween the bracket 10 and the surface of the tooth. More particularly,the deeper recessed surface 116 of the mold 108 preferably has a surfacefinish of approximately a maximum of 110.8 micro-inches. In contrast,preferably the mold perimeter rail walls 118 of mold 108 are polished toa smooth finish to prevent an injected bracket 10 from sticking to themold 108 during the ejection process, thereby preventing ejection orotherwise causing detrimental structural damage to the bracket 10 duringthe ejection process.

Referring now to FIG. 18, an alternate aspect of the invention is shown.FIG. 18 presents a pattern of characters 94, wherein the characters area three-pronged shape resembling the letter “Y”. As in the previouslydescribed embodiments, intermediate space 96 surrounds the characters 94within the interior region 88 of the base 16. Accordingly, the presentinvention contemplates the use of patterns of characters 94 wherein thecharacter is a seemingly arbitrary shape, and one in which the base 16possesses a projected surface 90 and a recessed surface 92. Brackets 10that included patterns of characters 94 of shapes may further includediscontinuous perimeter rail structures as described above.

Referring now to FIG. 19, in a separate aspect of the invention, apattern of characters 94 can be integrated into a side or labialposition on the bracket 10. For example, as shown in FIG. 19, theflanges 32 can include a pattern of characters 94 such that thecharacters 94 are visible from a front view of the bracket 10. Thepattern 94 could be a trademark of a manufacturer, a message, and/or thepattern 94 may be an ornamental or fanciful design.

In summary, the present invention is unique in that it provides a devicefor providing a continuous pattern of characters on the base of anorthodontic bracket. Characters are preferably formed by creating arecessed pattern of characters in the base, with the area between thecharacters raised, such that the area between the characters is closerto the tooth surface when the bracket is applied to the surface of apatient's tooth using an adhesive. Alternatively, the characters may beraised and projecting relative to the area between the characters, suchthat the characters are closer to the tooth surface when the bracket isattached to the surface of a patient's tooth.

In a separate aspect of the invention, a discontinuous perimeter railmay be used around the character pattern of the base. Preferably, thediscontinuous perimeter rail includes four separate corner sections andtwo additional separate straight sections along the gingival andocclusal edges of the base. When used, the discontinuous perimeter railprojects beyond the patterned surface of the base, such that thediscontinuous perimeter rail is closest to the tooth surface when thebracket is attached to a patient's tooth. The discontinuous perimeterrail increases the bonding strength of the bracket to the tooth'ssurface.

The substantially continuous pattern of characters and intermediatespace formed on the base of an orthodontic bracket provides a texturingpattern (e.g., an ordered array of projecting features) for bonding thebracket to a patient's tooth using an adhesive, while at the same timeproviding a means of presenting information about the bracket on itsbase surface by advantageously utilizing characters that representpertinent information, such as the name of the bracket manufacturer, theintended location for the bracket placement, or a graphics symbol orlogo.

The invention presented herein has been described with respect topreferred embodiments; however, other changes and modifications to theinvention may be made which are still contemplated within the spirit andscope of the invention.

The foregoing description of the present invention has been provided forpurposes of illustration and description. This description is notintended to limit the invention and various modalities thereof.Variations, embodiments and modifications will be apparent to thoseskilled in the art and are intended to be within the scope of thefollowing claims.

What is claimed is:
 1. An orthodontic bracket comprising: a body havingan archwire slot to accommodate an archwire, said archwire slot havingat least one of a convex sidewall and a floor portion adapted to reducearchwire bracket frictional engagement, and an auxiliary slot extendingin a gingival/occlusal direction under said floor portion, saidauxiliary slot configured to receive one of a steel ligature or anauxiliary shaft, said auxiliary slot being open at either end thereof,and having a surface including two or more characters selected from thegroup consisting of letters and numbers that are spaced apart from eachother, said two or more characters being projected from said surface andhaving spaces between said two or more characters being recessed,wherein the two or more characters have different dimensions, said bodycomprising a material selected from the group consisting of plastic,metal, and ceramic, wherein said two or more characters convey to a userof said bracket information selected from the group consisting of: amodel number, a manufacturer, a trademark, and a logo.
 2. The bracket asclaimed in claim 1, wherein said auxiliary slot has square corners. 3.The bracket as claimed in claim 1, wherein the two or more characters inthe auxiliary slot have a rounded exterior surface.
 4. The bracket asclaimed in claim 1, wherein said bracket has a flange.
 5. The bracket asclaimed in claim 1, wherein said archwire slot is positioned under saidarchwire slot to conserve a height of the bracket and enhance patientcomfort.
 6. The bracket as claimed in claim 1, wherein said two or morecharacters have different dimensions.
 7. An orthodontic bracketcomprising: a body comprising a material selected from the groupconsisting of plastic, metal, and ceramic having an archwire slot toaccommodate an archwire and an auxiliary slot passing under the archwireslot, said auxiliary slot configured to receive one of a steel ligatureor an auxiliary shaft, said auxiliary slot, having a surface includingtwo or more characters selected from the group consisting of numbersthat are spaced apart from each other, said two or more characters beingrecessed from said surface and having spaces between said two or morecharacters being projected, wherein said two or more characters conveyto a user of said bracket information selected from the group consistingof: model number, manufacturer, date of manufacture, lot number,distributor, placement data, part number and bracket data.
 8. Thebracket as claimed in claim 7, wherein said archwire slot extendsgingivally.
 9. The bracket as claimed in claim 7, wherein the two ormore characters are integrated into the auxiliary slot.
 10. The bracketas claimed in claim 7, wherein the two or more characters have a roundedexterior surface.
 11. The bracket as claimed in claim 7, wherein the twoor more characters have different dimensions.
 12. The bracket as claimedin claim 7, wherein said auxiliary slot extends gingivally/occlusually.13. The bracket as claimed in claim 7, further comprising a secondauxiliary slot, wherein each one of the auxiliary slot and the secondauxiliary slot is on each side of a gingival-occlusal center plane ofthe bracket.
 14. The bracket as claimed in claim 7, wherein saidauxiliary slot has square corners.
 15. The bracket as claimed in claim7, wherein each of said two or more characters have a width of betweenabout 0.034 and 0.038 inches and a line width of from between 0.008 and0.010 inches.
 16. The bracket as claimed in claim 7, wherein saidarchwire slot is positioned under said archwire slot to conserve aheight of the bracket.
 17. The bracket as claimed in claim 7, whereinsaid bracket has a flange that includes characters that convey to a userof said bracket information selected from the group consisting of: amodel number, a manufacturer, a trademark and a logo.
 18. An orthodonticbracket comprising: a body comprising a material selected from the groupconsisting of plastic, metal, and ceramic having an archwire slot toaccommodate an archwire and at least one auxiliary slot that passesunder a floor portion of the bracket, said auxiliary slot configured toreceive one of a steel ligature or an auxiliary shaft, said auxiliaryslot being open at either end thereof, and having a surface includingtwo or more characters selected from the group consisting of letters andnumbers that are spaced apart from each other, said two or morecharacters being molded to depict a trademark, name, symbol, logo, orpart number, wherein each character has a width of between about 0.034and 0.038 inches and wherein a line width of each character is frombetween 0.008 and 0.010 inches.
 19. The bracket as claimed in claim 18,wherein the two or more characters form a pattern of a trademark. 20.The bracket as claimed in claim 18, wherein said auxiliary slot extendsgingivally/occlusually.